I am reading here some ominous comments re the CDI [for my old 1994 400 cc 2 stroke etc]

seems some people have had to replace it several times

my question is, do these either work/not work [ie no spark at all] or can they simply give a weak spark, not enough to kick engine over?

 

<div class="FTQUOTE"><begin quote>Originally posted by: thedoc

I am reading here some ominous comments re the CDI [for my old 1994 400 cc 2 stroke etc]



seems some people have had to replace it several times



my question is, do these either work/not work [ie no spark at all] or can they simply give a weak spark, not enough to kick engine over?</end quote></div>

[img]i/expressions/face-icon-small-happy.gif[/img] The old rule years ago was that a cdi worked or didn't! But I've found at times that a bad cdi can spark ONCE through the coil each time you hit the ignition switch! Coils can do the same thing! I had one tech working with me about 10 years back that came from a Honda dealership and we took in a trx 200 for no fire. He disconnected the cdi,DROPPED it on the floor,hooked back up and it ran for a while! We replaced the cdi,ran like a new one! Just goes to show anything and everything can happen when dealing with electrical problems! As far as cdi and coil problems on the old 400 2-strokes, they are pretty reliable,had more problems with stators and reverse limiters shorting out,causing spark loss,BUT nothing beats a manual and and a good ohm meter to track down problems!

 

sorry I did not see your reply at the time old tech, but thanks for the answer

might sound like I am taking a long time to get this polaris working but it is not in a garage and as soon as I get the tarp off it starts to rain again [monsoon/cyclone season] but I have noted all suggestions.

I have had similar experience with CDI

1. in 1970s had a 1972 Triumph V8 Stag and did aftermarket replacement of points with a Pirahna CDI - after 2 years the car would just stop dead but if you twisted the escapsulated black box a bit it came good. Piraha replaced it and admitted they got fine cracks on the PCBs after encapsulating

2. in my current poverty as retiree with no superannuation I drive a 1976 volvo and CDI came as original but as an "exposed" PCB in a plastic box. Same thing happened and by poking around with it on roadside it would suddenly come good for a few miles, then repeat above. Got second hand unit at $75 [new one was a grand] and 14 years later still going fine, but old one still sits in boot [trunk] just in case.

funny things CDI

You say,

"BUT nothing beats a manual and and a good ohm meter to track down problems! "

I googled to manual by Clymer for my model. The preview [with strategic pages missing] looks very well presented and a $21 [big ones, so about $30 in my dollars] seems OK. Would you recommend this one?

 

Clymer is prettty good, they copy most pages from the Polaris service manual.